Sign made by wife leaving those of her sex (4)
I believe the answer is:
omen
'sign' is the definition.
(omen is a kind of sign)
'wife leaving those of her sex' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is present in the answer.
The remaining letters 'men' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'made by' is the link.
Can you help me to learn more?
(Other definitions for omen that I've seen before include "Augury, portent" , "Harbinger, augury" , "Event regarded as a prophetic sign of good or evil" , "Prophetic significance" , "Portent of things to come" .)